1. Field of the Invention
This invention relates to a metallic base paint, and more particularly, to a composition, useful as a metallic base paint, and containing a silyl group containing vinyl type resin containing at least one silicon atom attached to a hydrolyzable group at a terminal or in a side chain of its molecule.
2. Description of the Prior Art
The present inventors have previously discovered that vinyl type resins containing at least one silicon atom attached to a hydrolyzable group at the terminal or in a side chain in the molecule have, in addition to excellent characteristics inherent to vinyl type resins, e.g. higher luster, weather resistance, discoloration resistance, improved adhesion to inorganic substances due to the hydrolyzable silyl group, etc. Moreover, such resins can form minute networks by crosslinking at ambient temperature upon exposure to moisture, especially ambient atmospheric moisture. Thus, the resins have excellent solvent resistance, water resistance, heat resistance, high hardness, weather resistance, etc.
Generally, a metallic luster coating is achieved by coating a metallic base paint containing a metal powder, e.g. an aluminum powder, etc, and either while it is wet or after it has been dried coating thereon a topcoat transparent paint, and drying. Recently, however, to meet strong demand for speeding up the coating step, it is more frequently now the practice to coat the base paint and thereafter coat a topcoat, after only a brief interval of time. Such a practice, however, is accompanied by a problem. After the topcoat has been applied to the coated metallic base paint, the metal powder distributed in the paint is often swept away, or the resin in the base paint is often dissolved by the coating of the topcoat, to sweep away the metal powder. Thus, disadvantageously, the metallic luster is rendered non-uniform. In order to solve such a problem, various measures have been used, such as use of a high molecular weight resin, use of a highly volatile solvent, etc. However, these prior art solutions are restricted and deficient in the choice of kinds of resin and solvent or diluent.
Accordingly, there exists in the art, a need for a metallic base paint which does not have the aforementioned deficiencies and disadvantages.